Collaborative Research: Atmospheric Controls on Northern Hemisphere Cryosphere Variability

摘要ATM-9314721罗宾逊，大卫·A·罗格斯大学，新不伦瑞克标题：大气对北半球冰冻圈可变性的控制该奖项支持对大气可变性与北半球雪和海冰覆盖的海冰波动之间关系的全面研究。这项工作的主要目的是提供冰冻层对大气环流区域变化的敏感性的半球综合，并针对降水、温度、风和大尺度遥相关模式之间的相关相互作用诊断这种敏感性。PIS将确定冰冻圈中哪些区域需要重点监测潜在的气候变化，以及未来冰冻圈对环流制度变化的可能反应。作为这些努力的一部分，他们将对观测到的积雪模式与不同GCM在当前和预测未来气候条件下模拟的积雪模式进行一系列相互比较。这项研究将解决至少六个基本问题：1)北半球海冰面积的变化与陆地积雪之间的关系？2)冰冻圈的哪些地区对大气环流变化表现出较强或较弱的响应？为什么？3)哪些地区对北半球冰冻圈变化的贡献最大？4)冰冻圈对大尺度遥相关型模式的响应是什么，这些与天气活动、温度和降水的平行异常相比如何？5)不同的GCM描述当今积雪的分布和变化的情况如何，从模拟环流变化的观点来看，GCM预测的冰冻圈变化对二氧化碳变暖的影响是否合理？6)冰冻圈可以作为气候变化的有力指标吗？对于雪和海冰的分析，北半球积雪范围和海军/NOAA冰浓度数据的格网NOAA图将与现有的雪深、降雪、降水和地表温度的站点记录相结合。在大气分析方面，PIS将使用从20世纪60年代初到现在每天一至两次的NMC地面和高空场，用于计算气旋和反气旋的频率、位置和强度、风暴路径和其他天气活动指数(例如正涡度平流)以及温度的网格点和区域时间序列。来自现有档案馆的Rawinsonde数据将用于分析水汽通量汇聚的模式及其与北部高纬度积雪和降水变化的关系。对于加倍的二氧化碳(平衡)运行、瞬时运行(其中二氧化碳不断增加)，以及使用相同的当前边界条件的运行，将获得不同GCM的输出。这项研究是科罗拉多大学(马克·塞雷兹博士和罗杰·G·巴里博士)和罗格斯大学(大卫·罗宾逊博士)的合作成果。这项工作之所以重要，是因为它试图澄清冰冻圈在气候变化中的作用。

Abstract ATM-9314721 Robinson, David A. Rutgers University, New Brunswick Title: Atmospheric Controls on Northern Hemisphere Cryosphere Variability This award supports comprehensive study of relationships between atmospheric variability and fluctuations in the snow and sea ice covers the Northern Hemisphere. The primary thrust of the work is to provide a hemispheric synthesis of the sensitivity of the cryosphere to regional changes in the atmospheric circulation, and to diagnose this sensitivity with respect to associated interactions between precipitation, temperature, winds and the modes of large-scale teleconnection patterns. The PIs will identify those regions of the cryosphere warranting focused monitoring for potential climate change, and possible future responses of the cryosphere to changes in circulation regimes. As part of these efforts, they will perform a series of intercomparisons between observed snow cover patterns and those simulated by different GCMs under present and project future climatic conditions. The study will address at least six basic questions: 1) What are the relationships between variations in northern hemisphere sea ice extent and terrestrial snow cover? 2) What areas of the cryosphere exhibit strong or weak responses to atmospheric circulation changes and why? 3) Which areas contribute most strongly to northern hemisphere cryosphere variability? 4) What are the responses of the cryosphere to the modes of Large-scale teleconnections patterns, and how do these compare with parallel anomalies in synoptic activity, temperature and precipitation? 5) How well do different GCMs depict the present day distribution and variability of snow cover, and are changes in the cryosphere projected by GCMs in response to enhance CO2 warming reasonable from the viewpoint of modeled circulation changes? 6) Can the cryosphere be used as a robust indicator of climate change? For the snow and sea ice analyses, gridded NOAA charts of Northern Hemisphere snow extent and Navy/NOAA ice concentration data will be combined with available station records of snow depth, snow fall, precipitation and surface temperature. For atmospheric analyses, the PIs will use once to twice-daily NMC surface and upper-air fields from the early 1960s to present, used to calculate grid- point and regional time series of the frequency, position and strength of cyclones and anticyclones, storm tracks, and other indices of synoptic activity (e.g, positive vorticity advection), as well as temperature. Rawinsonde data from an existing archive will be used to analyze patterns of moisture flux convergence and their associations with snow cover and precipitation variations at high northern latitudes. Output from different GCMs will be obtained for doubled CO2 (equilibrium) runs, transient runs (in which CO2 is continually increased), as well as for runs using identical present-day boundary conditions. The research is a collaborative effort between University of Colorado (Drs. Mark Serreze and Roger G. Barry) and Rutgers University (Dr. David Robinson). The work is important because it seeks to clarify the role of the cryosphere in climate variability.